Compounds containing (meth)acrylate groups and sulfonate or sulfate groups, polymers and condensates made therefrom and use of the polymers and condensates

ABSTRACT

The invention relates to a compound, comprising at least three functionalities, that is (a) a sulfonate or sulfate group of the formula —(O) d —SO 3 M with d=0 or 1 and M=hydrogen or a monovalent metal cation or the corresponding fraction of a polyvalent metal cation, (b) a (meth)acryl group, and (c) either (c1) at least one further (meth)acryl group or an inorganically condensable group, and/or (c2) a further carboxylic acid function, and/or (c3) a function which increases the refractive index of a material produced from the compounds, that is a thioether group, with the proviso that a sulfonate or sulfate group and a (meth)acrylate group are separated from one another in a silicon-free compound via a hydrocarbon-containing group, the carbon chain of which is either interrupted by O, S or NH or contains a linking group.

The present invention concerns compounds with at least one (meth)acrylresidue, at least one sulfonate or sulfate group as well as a further,usually reactive group, their polymerization products as well as the useof the monomers and the polymers in the medical field, in particular indentistry. Inasmuch as the invention concerns silane compounds, it alsoencompasses the condensates available from them as well as their use.

Polymerizable organic compounds with acid groups are importantcomponents for medical products for achieving desired materialproperties like wetting, etching effect, complexing, and therebyadhesion on biological interfaces. Dental adhesives are based on suchconventional monomeric compounds, but exhibit still some considerabledeficits. An essential problem in this context is that the etchingeffect is often insufficient within the context of self-etch applicationfor realizing the necessary retentive structures required for theadhesion and thus a long-lasting connection between dental tissue andrestoration material. Therefore, a prior separate etching step with anetching gel cannot be avoided; this, in turn, increases thesusceptibility for errors and the treatment costs. Concerning theincreasing demands in regard to biocompatibility (reference is being hadto the allergy discussion in connection with dental monomers), the abovesystems also offer no solution. Since the components of the adhesive incase of a restoration come closest to the tooth roots as well as bloodvessels, it is of special interest from a toxicological viewpoint toprovide systems that are free of monomers.

In the patent application DE 44 16 857 C1, carboxylicacid-functionalized (meth)acrylate alkoxysilanes are described. They arecharacterized by a plurality of possibilities for varying or adjustingthe properties of the inorganic-organic composite polymers producedtherefrom. As a result of the contained carboxylic acid groups,additional reaction possibilities (e.g., glass ionomer reactions) aswell as an improved adhesion on inorganic surfaces arise. The etchingeffect (see self-etch application) of a carboxylic acid group is howevernowhere as strong as it is sometimes desired. The same holds true forthe phosphonic acid-based systems disclosed in EP 1 377 628 B1.Therefore, up to now, it is not possible to obtain with hybridpolymer-based systems a stable enough connection between dental tissueand restoration material in the context of the desirable self-etchapplication.

For several application purposes, like the stabilization of aqueoussilicates or the production of electro-viscous liquids, emulsifiers,detergents or foaming agents, monomeric or condensed silanes containingsulfonate or sulfate groups have been developed. Thus, U.S. Pat. No.6,777,521 discloses silicone sulfate polymers which are obtainable bythe reaction of suitable epoxy compounds with metal sulfate. U.S. Pat.No. 3,328,449 discloses sulfopropylated organo-functional silanes andsiloxanes which can be obtained by means of reacting sultones. Organosiloxane sulfosuccinates in which a sulfonated succinic acid ester isbonded by the oxygen atom of the ester group by an alkylene group to asilicon atom are disclosed in U.S. Pat. No. 4,777,277. The preparationof a hydrolytically condensable bis-sulfosuccinate amide of adiaminosilane, obtained by the reaction of the free carboxylic acid ofthe corresponding succinate amide with sodium sulfite, is disclosed inexample 1 of U.S. Pat. No. 4,503,242. A silane which carries a sulfonategroup and a hydroxyl group at an alkylene oxyalkylene residue of thesilicon is disclosed in U.S. Pat. No. 5,427,706.

The use of purely organic monomers which carry a terminal sulfonategroup as well as an unsaturated olefinic group for concurrent etchingand base-coating (“priming”) of teeth is suggested in US 2002/0119426A1. The employed AMPS (2-acrylamido-2-methylpropane sulfonic acid) is acommercially available product. U.S. Pat. No. 6,759,449 B2 alsodiscloses dental adhesive compositions which carry an organicallypolymerizable (meth)acrylic acid group as well as an acidic group. Inthis context, no distinction is made between sulfonate groups andphosphonate groups or other acidic groups concerning the usability ofthe compounds and their properties. The same holds true for US2003/0055124 A1; only for the (meth)acrylamido phosphonic acids, but notfor the also disclosed corresponding sulfonic acids, information isprovided for the preparation. Another application, US 2008/0194730,essentially by the same group of inventors, suggests again for dentalcomposites the use of self-etch polymerizable N-substituted(meth)acrylic acid amide monomers which carry additionally an acidicunit, selected from phosphonic acid units and sulfonic acid units.N-methacryloyl aminoalkyl sulfonic acids can be used according to thedisclosure of EP 1 421 927 A1 as self-etch primers for dental purposes.

DE 102 06 451 A1 discloses dental adhesive compositions from acidicallypolymerizable nanoparts in an aqueous phase. The nanoparticles consistof siloxanes having acidic as well as organically polymerizable groupsbonded thereto. The acidic groups can be either phosphonate groups orsulfonate groups; individual specific advantages for one or the othergroup are not specified. The only example of use discloses a specificadhesion value of a dental adhesive, made from a phosphonicacid-containing material, on a tooth surface. A process for producingsulfonate group-containing silanes is neither mentioned generally nor inregard to the illustrated compounds.

There is a need for organically polymerizable monomers of superiorproperties for the application in particular in the dental field. Here,an improved adhesion and/or an improved etching function and/or anadaptation of the optical properties for the cosmetic appearance areespecially relevant. To provide a remedy in this context is the objectof the present invention.

As a solution to this object, compounds are provided which comprise atleast three functionalities, namely (a) a sulfonic acid or sulfonategroup of the formula —(O)_(d)—SO₃M, with d=0 or 1 and with M=hydrogen ora monovalent metal cation or the corresponding portion of a multivalentmetal cation, for a very good etching effect, (b) a (meth)acryl residueas an organically polymerizable group by which the material can be curedafter the application on or in the tooth, as well as (c) either (c1) atleast one further (meth)acryl residue or an inorganically condensablegroup in order to enable an especially good crosslinking of the dentalmaterial, and/or (c2) a further acid function to improve the etchingeffect of the molecule, and/or (c3) a function by which the refractiveindex of a material made from the compounds increases, which leads to animproved translucence and thus an improved adaptation to the toothcolor. The acid function according to (c2) can be an additional sulfonicacid group or sulfuric acid group; alternatively, another acidic groupcan be present, for example, a carboxylic acid group.

Compounds which contain (a) a sulfonate group, (b) an acryl group or amethacryl group and (c) a silyl group are excluded preferably from theinvention in case that these compounds contain a trivalent nitrogen atomand each of the three groups (a), (b), and (c) is bonded to anothersubstituent of the nitrogen atom, provided that the (meth)acryl group iscoupled as (meth)acrylamide or the acryl group is coupled to thenitrogen atom by the methyl group coupled as a substituent at C2, inparticular when the sulfur atom of the sulfonate group is separated bythree or four carbon atoms from the nitrogen atom. Above all, the threefollowing compounds, which are disclosed in DE 102 06 451 A1 and U.S.Pat. No. 7,041,709 without these publications indicating a possibilityfor producing them, should optionally not be encompassed by theinvention:

(RO)₃Si(CH₂)₃N[(CH₂)_(x)SO₃Na][C(O)C(CH₃)═CH₂] with x=3 and x=4 and

(RO)₃Si(CH₂)₃N[(CH₂)₃SO₃Na][CH₂C(═CH₂)C(O)OR] wherein the substituents Rin each case, independently of each other, are hydrogen, a substitutedor unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted orunsubstituted alkylene or alkenyl group, optionally containing a cyclicstructure, with 2 to 20 carbon atoms, a substituted or unsubstitutedalkylaryl group, a substituted or unsubstituted arylene or aryl group,or a substituted or unsubstituted hetero arylene or hetero aryl group,in each case with 5 to 20 carbon atoms.

The inventors have succeeded in discovering ways for the preparation ofcompounds which comprise organically polymerizable groups, in particular(meth)acryl groups, as well as sulfate or sulfonate groups and which arecharacterized by at least one additional group, selected from a further(meth)acryl residue, an inorganically condensable silyl residue, and afurther acid function. Instead of the additional group, or also inaddition however, the compounds can have a thioether group by which therefractive index of dental materials made from the compounds increases.

In a first embodiment of the invention, the compounds according to theinvention are silanes which can be represented by the following formula(I):

R⁷ _(a)R² _(b)SiZ_(4-a-b)  (I)

wherein R⁷ is a hydrolytically (i.e. under hydrolysis conditions)condensable residue; R² an alkyl, aryl, arylalkyl, alkylaryl oralkylarylalkyl that is substituted or unsubstituted, straight chain,branched or has at least one cyclic structure, as an exception it can beinstead a corresponding alkenyl or can encompass an alkenyl whose carbonchain in all cases optionally can be interrupted by —O—, —S—, —NH—,—S(O)—, —C(O)NH—, —NHC(O)—, —C(O)O— —C(O)S, —NHC(O)NH— or C(O)NHC(O)groups which can optionally be oriented in both possible directions; Zis a residue in which are present at least one (meth)acryl group and atleast either a sulfonate group or a sulfate group that are bondeddirectly or indirectly by an unsubstituted or substituted hydrocarbongroup to the silicon atom; a is 1, 2 or 3; b is 0, 1 or 2; and a+btogether are 2 or 3.

As a result of the suggested preparation methods according to theinvention, silanes of the formula (I) are preferred in which, when asulfonate group is bonded by an alkylene group interrupted by one orseveral nitrogen atoms to the silicon atom, either no more than twocarbon atoms exist between the sulfonate group and the nearest nitrogenatom or, instead, this alkylene group is interrupted by at least one—O—, —S—, —NH—, —C(O)NH—, —NHC(O)—, —S(O)— or —C(O)O— group.

The structures of these new silanes are shown in abstraction in the twofollowing schematic drawings. The alkoxysilane part (present k times,i.e. more than one silyl residue can be present in the molecule whichcan be the case, e.g., in case of a compound in which two or more(meth)acrylic acid residues are organically linked with each other andare bonded in the indicated manner to an Si atom, respectively) can beused as usual within the scope of the sol gel process generally used forthe preparation of silicic acid (poly)condensates for building theinorganic oligomer or polymer structure. In the present case, the lattercan also have, as is known from the prior art, the form of dimeres,chains, rings, ladders (i.e. two-dimensional surfaces) orthree-dimensional spatial structures, as a function of the number of thehydrolytically condensable residues and the respective hydrolysisconditions. The organically polymerizable molecule part consisting of avariable number m of double bonds in R′₆ which are bonded to the silanepart can be used for building an additive organic network. The linkingunit is of organic nature and variably in length, structure andcomposition. All molecule parts can be used for modification of theproperties.

In this context, the groups and indices have the following meaning:

R′₂ is OH or a salt —OM with M=a monovalent metal cation or thecorresponding portion of a multivalent metal cation, preferably selectedfrom alkali and alkaline earth cations, in particular Na, K, ½ Ca, ½ Mg,or ammonium,X means oxygen or is not present,R′₃, R′₄, R′₅ are either residues which can be subjected with formationof Si—O—Si bridges to a hydrolytic condensation, such as OH, —OR,halogen, e.g., Cl, or residues which are bonded by a carbon atom to thesilicon atom; in the simplest case the latter is methyl,R′₇ defines the organic residue which has the sulf(on)ate group as wellas the double bond-containing residue; the latter is bonded by a carbonatom to the silicon.R′₆ is a double bond-containing residue, usually a (meth)acryl residue.

refers to an organic residue which is interrupted as a result of theselected reaction control generally at least by one linking group or anoxygen atom, a sulfur atom, or a secondary or tertiary amino group. Aslinking groups, in the present case primarily —C(O)O— and —C(O)NH—groups are used; instead, however, also —NHC(O)—, —NHC(O)O—,—C(O)NHC(O)—, —NHC(O)NH— —S(O)— or the corresponding sulfur-containinggroups can serve as links.R′₈ means —CO₂H or OH.n, m and j mean in each case at least 1, but can be in certain cases 2or 3 or even an even higher value.

In a second embodiment of the invention, the compounds according to theinvention can be represented by the following formula (II):

whereinR¹ is a bivalent hydrocarbon residue which, provided that f=1, is bondedby a carbon atom to the silicon atom,R⁹ is H or alkyl and, in addition, in case of a=0, f=1, and g=1, can bea hydrolytically condensable residue other than alkoxy or

R³ is an alkylene that is unsubstituted or substituted with a functionalgroup, straight chain, branched or has at least one cyclic structure,A is a linking group,R⁴ is a hydrocarbon group that is optionally interrupted by O, S, NH orNR⁸ and/or optionally functionally substituted, preferably is analkylene of this type,M is hydrogen or a monovalent metal cation or the corresponding portionof a multivalent metal cation, preferably selected from alkali andalkaline earth cations, in particular Na, K, ½ Ca, ½ Mg, or ammonium,R⁵ and R⁶, independently of each other, are either residues that arecondensable under hydrolysis conditions or alkyl, aryl, arylalkyl,alkylaryl or alkylarylalkyl, substituted or unsubstituted,straight-chain, branched or having at least one cyclic structure, inexceptions, however, they can also be a corresponding alkenyl,arylalkenyl or alkenylaryl instead,R⁸ is alkyl or alkenyl with preferably 1 to 6 or 2 to 6 carbon atoms ora (meth)acryl residue,B is vinyl, 2-allyl or, in case of e>1, an organic residue with e vinylgroups that are present in each case bonded to a group located in thecurly brackets,Y is a nitrogen atom, —O—CH═, —S—CH═ or —NH—CH═, wherein in each casethe oxygen atom, the sulfur atom or the NH group has a bond to theadjacent C(O) group,a is =0 or 1,b is =0 or 1,c is =0 or 1,d is =0 or 1, e is =1, 2 or 3f is =0 or 1 andg is =0 or 1,wherein then, when f is =1, a and g both are ≠0, andwherein, when f=0, then at least one of the residues R³ or R⁴ carries afunctional substituent which has a (meth)acrylate residue or an acidicgroup or R⁴ is an alkylene that is interrupted at least by S.

In a specific variant of the second embodiment, when in the formula (II)Y is a nitrogen atom, b=0, c=0, and preferably also d=0, the residue R³must be an optionally substituted ethylene, and likewise, when Y is anitrogen atom, b=0, c=1 and preferably also d=0, the residue R⁴=analkylene that is interrupted by O, S, NH or NR⁸ and optionallyfunctionally substituted.

When f and also g are =0, then a is preferably also 0.

In several preferred embodiments, the silanes according to the inventionof the formulae (I) or (II) can be represented by the following formula(Ia):

whereinR¹ is a hydrocarbon group as defined above bonded by a carbon atom tothe silicon atom,R⁷ is a hydrolytically condensable residue,and the residues R³, R⁴, R⁵, R⁶, B and Y as well as the indices b, c, d,and e are the same as defined for formula (II).

In a specific variant of the formula (Ia), when in the formula (II) Y isa nitrogen atom, b=0, c=0 and preferably also d=0, then the residue R³must be an optionally substituted ethylene, and also, when Y is anitrogen atom, b=0, c=1 and preferably also d=0, then the residueR⁴=alkylene that is interrupted by O, S, NH or NR⁸ and optionallyfunctionally substituted.

According to the above formulae, the sulf(on)ate residue or residues aswell as the (meth)acryl residue or residues can be bonded directly orindirectly to the hydrocarbon group that is comprised at least of R¹. Inthe terminology of the invention, the expression “directly” is to beunderstood such that the aforementioned residues are bonded to thesilicon without further interruptions of the carbon chain of the alkylgroup by S, O, NH or a coupling group. “Indirectly” means accordinglythat these residues are coupled to components of the molecule, whereinbetween them and the alkyl group bonded to the silicon theaforementioned atoms or groups are present, as is evident, e.g., for theresidue SO₃M in formula Ia for the case that b=1 is or that c=1 with R⁴being a group interrupted by O, S, NH or NR⁸.

The bivalent hydrocarbon residue R¹ can be in all embodiments of theinvention an alkylene group, an arylene group or a group which hasalkylene as well as arylene units. The alkylene group can bestraight-chain or branched and/or have at least one cyclic component. Inthis context, the group can be bonded by an alkylene carbon atom or byan arylene carbon atom to the silicon atom. It is unsubstituted orunsubstituted, and it can be interrupted by one or several oxygen atoms,sulfur atoms, ester groups, amino groups or amide groups.

The linking group A in the formulae (Ia) and (II) is preferably selectedfrom (read from the left to the right in the formulae Ia and II) C(O)NH,NHC(O), NR⁸C(O), C(O)O and OC(O) and R⁸ is defined as above. Inexceptions, the linking group A can also be selected additionally fromNHC(O)O, NR⁸C(O)O, NHC(O)NH, C(O)NHC(O) and —C(O)S—. The residue R⁴ inthese formulae is substituted in specific embodiments with at least onehydroxyl group and/or with a residue R⁹COOM wherein R⁹ is a chemicalbond or a C₁-C₆ alkylene residue and M is hydrogen or the correspondingportion of a multivalent metal cation, preferably selected from alkaliand alkaline earth cations, in particular Na, K, ½ Ca, ½ Mg, orammonium. The aforementioned variants can be realized independently orin combination.

Residues R⁷ in formula (I) as well as residues R⁵ and/or R⁶ in theformulae (Ia) and (II) which can condense under hydrolysis conditionsare referred to as inorganic network formers because through them, byhydrolytic condensation reaction, a silicic acid polycondensate networkis formed. A person of skill in the art knows accordingly with whichnumber of these residues which oligomer or polymer structure isobtainable and which meaning they can have. Preferably R⁵ and R⁶ are OHor a C₁-C₁₀ alkoxy group, more preferred a C₁-C₄ alkoxy group, andparticularly preferred methoxy or ethoxy. R⁷ can have the same meaningas R⁵ and/or R⁶. However, R⁵, R⁶ and R⁷ can be, as needed, independentlyof each other, also a halide such as Cl, hydrogen, acyloxy withpreferably 2 to 5 carbon atoms, alkylcarbonyl with preferably 2 to 6carbon atoms or alkoxycarbonyl with preferably 2 to 6 carbon atoms. Insome cases, they can have, instead, the meaning NR² with R² beinghydrogen, alkyl with preferably 1-4 carbon atoms, or aryl withpreferably 6-12 carbon atoms.

The expression “sulf(on)ate” encompasses the sulfonate group and thesulfate group. The expressions “sulfonate group” and “sulfate group”encompass the respective acids and salts.

The word or the word part “(meth)acryl . . . ” is meant to encompass therespective methacryl and acryl compounds alike. The (meth)acryl residuescan be in particular a component of a (meth)acrylic acid ester,(meth)acrylic acid thioester or (meth)acrylic acid amide. Compared withthe other (meth)acryl residues, (meth)acrylic acid amide residues arepreferred because of their better resistance to hydrolysis.

One aspect of the invention resides in that, for building the chemicalstructures of the compounds (II), an easy incorporation of the(meth)acryl groups can be achieved in that the latter are reacted in theform of the free acid or an activated acid. This has the result that the(meth)acryl group is incorporated as (meth)acrylic acid ester, amide orthioester in the structures.

With few exceptions, the syntheses are controlled such that a C═C doublebond is available for the addition of the sulfonic acid group or sulfategroup to the molecule that already contains a (meth)acryl group. Asneeded, to said double bond either sodium sulfite or a sulfonic acidwith a residue that is easily reacted by addition, such as thio oraminoalkane sulfonic acid, can be added. Alternatively, the attachmentof the sulfonic acid group can also be carried out by the reverseprinciple in that thio or aminoalkylsilane or a correspondingsilane-free compound is reacted with an alkylene sulfonic acid. Withthis process, a chain length extension by the carbon atoms of thealkylene group is of course inevitable, which is the reason why thefirst variant is preferred over the second. Finally, there is still thepossibility to cause ring opening of a reactive or strained hetero ring,in particular of a three-membered ring, by sulfite or a hydroxyl, thioor aminoalkane sulfonic acid. This variant has the advantage that thering opening reaction generates a further reactive group which can beused for the subsequent attachment of the activated (meth)acrylic acid.The hetero ring can be opened alternatively also by means of a sulfate;in these cases, a sulfate group-containing product is obtained.

As mentioned above, an embodiment of the invention concerns silanes ofthe formulae (Ia) or (II) with f=1 and g=1. As a result of the suggestedpreparation methods according to the invention, those silanes arepreferred herein which, when a sulfonate group is bonded by an alkylenegroup interrupted by one or several nitrogen atoms to the silicon atomor to the (optionally nearest) (meth)acryl group, either no more thantwo carbon atoms are present between the sulfonate group and the nearestnitrogen atom or, instead, this alkylene group is interrupted by atleast one —O—, —S—, —NH—, —C(O)NH—, —NHC(O)— or —C(O)O group.

All together, for the preparation of silanes with the formula (I), (Ia)or (II) with f=1, four basic variants are available according to theinvention as follows:

Variant (A):

-   (a) a silane with a hydrocarbon group bonded by a carbon atom to the    Si atom is provided which carries at least two functional groups,    selected from primary amines, secondary amines, hydroxyl groups and    thiol groups,-   (b) a first one of the two functional groups is reacted with    optionally activated (meth)acrylic acid and the second one of the    two functional groups is reacted with an optionally activated second    carboxylic acid having a C═C double bond and optionally at least one    further functionality, and-   (c) subsequent to the afore mentioned reaction, a sulfonate    group-containing or sulfate group-containing compound or a sulfite    is added to the C═C double bond of the carboxylic acid residue    reacted with the second functional group in such a way that at the    (meth)acryl residue reacted with the first one of the two functional    groups such an addition does not take place, which can be ensured in    different ways, e.g., by the molar ratio of the groups reacted with    each other, wherein the second carboxylic acid having a C═C double    bond can be a (meth)acrylic acid or another double bond-containing    carboxylic acid.

Purely in exemplary fashion, several possible aminosilanes will bementioned which can be used in step (a) as a starting material:

(aminoethylaminomethyl)phenylethyl trimethoxysilane,N-(2-aminoethyl)-3-aminopropyl methyldimethoxysilane,N-(2-aminoethyl-3-aminopropyl)trimethoxysilane,N-2-aminoethyl-3-aminopropyl tris(2-ethylhexoxy)silane,6-(aminohexylaminopropyl)trimethoxysilane,N—(N′-(2-aminoethyl)aminoethyl)-3-aminopropyl trimethoxysilane,N—(N′-(2-aminoethyl)aminoethyl)-3-aminopropyl methyldimethoxysilane,N—(N′-(2-aminoethyl)aminoethyl)-3-aminopropyl triethoxysilane,N—(N′-(2-aminoethyl)aminoethyl)-3-aminopropyl-methyldiethoxysilane,N—(N′-(2-aminoethyl)aminoethyl)-3-aminopropyl trimethylsilane,N—(N′-(2-aminoethyl)aminoethyl)-3-aminopropyltris(methoxyethoxyethoxy)silane.

Instead, comparable compounds with corresponding hydroxyl or thiolgroups could be used. These are disclosed, for example, in EP 0 779 890A1. Also, the hydrocarbon group can have a configuration other than thatshown in the examples shown above.

Variant (B):

-   (a) a silane with a hydrocarbon group bonded by a carbon atom to the    Si atom is provided which carries at least one reactive hetero ring,    selected from the three-membered rings oxacycyclopropyl (=epoxy),    azacyclopropyl, and thiocyclopropyl, and from cyclic carbonates (the    latter can be obtained by reaction of an epoxy ring with CO₂, but    also by other pathways, as disclosed in DE 44 23811 in detail),-   (b) the hetero ring is reacted with a sulfite or a sulfate or a    sulfonate group-containing or a sulfate group-containing compound,    and-   (c) at least the OH, SH or NH₂ group that is obtained in this way is    reacted with (meth)acrylic acid that is optionally activated.

Purely in an exemplary fashion, several possible epoxy compounds will bementioned which can be used in step (a) as a starting material:

Glycidoxymethyl trimethoxysilane, glycidoxymethyl triethoxysilane,2-glycidoxyethyl trimethoxysilane, 2-glycidoxyethyl triethoxysilane,3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane,3-glycidoxypropyl triacetoxysilane, 4-glycidoxybutyl trimethoxysilane,4-glycidoxybutyl triethoxysilane,glycidoxymethyl(methyl)dimethoxysilane,glycidoxymethyl(ethyl)dimethoxysilane,glycidoxymethyl(phenyl)dimethoxysilane,glycidoxymethyl(vinyl)dimethoxysilane,glycidoxymethyl(dimethyl)methoxysilane,2-glycidoxyethyl(methyl)dimethoxysilane,2-glycidoxyethyl(ethyl)dimethoxysilane,2-glycidoxyethyl(dimethyl)methoxysilane,3-glycidoxypropyl(methyl)dimethoxysilane,3-glycidoxypropyl(ethyl)dimethoxysilane,3-glycidoxypropyl(dimethyl)methoxysilane,4-glycidoxybutyl(methyl)dimethoxysilane,4-glycidoxybutyl(ethyl)dimethoxysilane,4-glycidoxybutyl(dimethyl)methoxysilane,bis-(glycidoxymethyl)dimethoxysilane,bis-(glycidoxymethyl)diethoxysilane,bis-(glycidoxyethyl)dimethoxysilane, bis-(glycidoxyethyl)diethoxysilane,bis-(glycidoxypropyl)dimethoxysilane,bis-(glycidoxypropyl)diethoxysilane,tris-(glycidoxymethyl)methoxysilane, tris-(glycidoxymethyl)ethoxysilane,tris-(glycidoxyethyl)methoxysilane, tris-(glycidoxyethyl)ethoxysilane,tris-(glycidoxypropyl)methoxysilane, tris-(glycidoxypropyl)ethoxysilane,glycidylmethyl trimethoxysilane, glycidylmethyl triethoxysilane,2-glycidylethyl trimethoxysilane, 2-glycidylethyl triethoxysilane,3-glycidylpropyl trimethoxysilane, 3-glycidylpropyl triethoxysilane,3-glycidylpropyl tri(methoxyethoxy)silane, 3-glycidylpropyltriactoxysilane, 3,4-epoxycyclohexylmethyl trimethoxysilane,3,4-epoxycyclohexylm ethyl triethoxysi lane, 3,4-epoxycyclohexylethyltrim ethoxysilane, 3,4-epoxycyclohexylpropyl trimethoxysilane,3,4-epoxycyclohexylbutyl trimethoxysilane.

Instead, comparable compounds with corresponding azacyclopropyl andthiocyclopropyl groups could be used. Also, the hydrocarbon group canhave a configuration other than that shown in the examples shown above.

Variant (C):

-   (a) a silane with a hydrocarbon group bonded by a carbon atom to the    Si atom is provided which has an amino group or a mercapto group,-   (b) an alkenyl sulfonate or a sulfone is reacted with the amino    group or the mercapto group, and-   (c) the secondary amino group or thio group produced in b. is    reacted with (meth)acrylic acid that is optionally activated.

Purely in an exemplary fashion, several possible aminosilanes which canbe used in step (a) as a starting material will be mentioned:

4-aminobutyl dimethylmethoxysilane, 4-aminobutyl triethoxysilane,aminomethyltrimethylsilane, aminophenyl trimethoxysilane,3-(1-aminopropoxy)-3,3-dimethyl-1-propenyl trimethoxysilane,3-aminopropyl diethylmethylsilane, 3-aminopropyltris(methoxyethoxyethoxy)silane, 3-aminopropyl dimethylethoxysilane,3-aminopropyl methyldiethoxysilane, 3-aminopropyl triethoxysilane,3-aminopropyl trimethoxysilane, 3-aminopropyltris(trimethylsiloxy)silane, and ω-aminoundecyl trimethoxysilane.

Variant (D):

-   (a) a (meth)acrylsilane with at least two (meth)acryl groups which    are bonded by a carbon atom of a hydrocarbon group to the silicon    atom is provided or produced according to the prior art, e.g.,    according to DE 44 16 857, and-   (b) a sulfonate group-containing or sulfate group-containing    compound or a sulfite is added in less than stoichiometric quantity    to the C═C double bond of one or several of the (meth)acryl residues    such that such an addition does not occur on at least one    (meth)acryl residue in the molecule, which can be ensured in    different ways, e.g., by the molar ratio of the groups reacted with    each other.

In the variants (A), (B) and (D), the sulfonate group-containing orsulfate group-containing compound contains preferably OH—, SH— or NHR¹⁰group with R¹⁰=hydrogen or C₁-C₆ alkyl. Examples of mercaptogroup-containing sulfonates are straight-chain or cyclic alkanesulfonate or aryl sulfonates, e.g., mercaptoethanesulfonate,mercaptobutanesulfonate, mercaptocyclohexylsulfonate ormercaptobenzenesulfonate. Their sodium salts are common.

A third embodiment of the invention concerns compounds of the formula(II) with f=0 and g=0 wherein at least one of the residues R³ or R⁴ (thelatter in case of c=1) carries a functional substituent which has a(meth)acryl residue and/or an acidic group or—in some cases—instead, orin addition, a thioether group. In this context, the functionalsubstituent can be the (meth)acryl residue or the acidic group or can bea unit comprising this residue/these residues.

To produce purely organic compounds, the above variants (A), (B) and (D)can be modified in a suitable manner in that corresponding compoundswithout silyl residue are used as starting materials. Concerning thepreparation variant (A), it should be noted that compounds according tothe invention are obtained when at least three double bond-containingacids are bonded to the starting material which can be realized, e.g.,in that a hydrocarbon-containing starting compound has at least three ofthe functional groups mentioned in (A)a. When to these three groups(meth)acryl residues are attached, a sulfonate group-containing orsulfate group-containing compound or a sulfite can be added either toone of them or to two of them. Compounds according to the invention areobtained also when a starting material with only two functional groupsis used wherein, however, at least one of them is reacted with theanhydride of a double bond-containing dicarboxylic acid. With reactionsanalogous to variant (B), compounds according to the invention areobtained when the hetero ring is reacted with a sulfonategroup-containing or sulfate group-containing compound such that anotherlinking site for binding an additional (meth)acrylate or a further acidis generated, i.e. when, e.g., an aminoalkane sulfonate is reacted withthe three-membered ring. An organic compound with at least three(meth)acryl groups is used instead of a (meth)acrylsilane in variant(D), for example, trimethylolpropane triacrylate. The sulfur-containingcompound can be added in a molar ratio such that the product containseither at least two (meth)acryl residues or at least two sulf(on)ateresidues. When in the variants (A), (B) or (D) a thioalkane sulf(on)ateis used, a thioether group is generated which can be considered in someembodiments as the third functional group aside from the at least one(meth)acrylate and the at least one sulf(on)ate group because itincreases the refractive index of the condensate producible from it, asexplained above.

Inasmuch as in the preparation methods of the invention activatedcarboxylic acids are to be used, the activation can be done according tocommon methods; thus, for example, acid chlorides or (intramolecular orintermolecular) anhydrides can be used.

Inasmuch as in the reactions of the invention inorganic sulfonates orsulfates are used, alkali, alkaline earth and ammonium salts aresuitable in particular for this purpose. Among the alkali salts, thoseof sodium and potassium and, among alkaline earth salts, those ofmagnesium and calcium are preferred. The silanes according to theinvention can comprise these salt groups or the corresponding free acidfunction.

The different reactions according to variant (A) will be explained belowin an exemplary fashion with the aid of the reactions 1, 2, and 7 inmore detail, wherein the reactions 1 and 2 show the preparation ofsilane compounds and reaction 7 the preparation of a compound free ofsilicon. In this context, reaction 7 follows the scheme of reaction 2.

For reaction 1, a starting silane with a hydrocarbon group which carriestwo amino functions was selected. The reaction occurs in a comparablemanner when instead of the primary terminal amine a hydroxyl or a thiolgroup is present. The secondary NH group could be absent; instead, thealkylene group bonded to the silicon could have a continuous carbonskeleton which would be substituted at a suitable site (e.g., at theposition in which in the example the secondary NH group is located) withNH₂, OH or SH. The starting silane can have optionally additionally asecond secondary amino group; in this case not only two, but threeacrylamide groups would be generated by the reaction with methacryloylchloride.

The length and the structure of the hydrocarbon group in the molecule isnot critical and can be selected arbitrarily. Thus, the hydrocarbon canbe alkyl that is straight-chain or branched or can have at least onecyclic structure. Moreover, the hydrocarbon can optionally besubstituted with other groups which do not take part in the reactions,or can be interrupted arbitrarily by hetero atoms or linking groups.

The substituents of the silicon indicated in reaction 1 by Me and OR canbe selected, as needed, arbitrarily, i.e., a suitable number ofhydrolytically condensable residues or of residues acting as networkmodifiers (alkyl groups, aryl groups and the like) can be present thatis suitable for the desired silicic acid (hetero) polycondensate. Inspecial embodiments two hydrocarbon groups that carry the reactivefunctions according to the invention can be present; the sum ofhydrolytically condensable residues and residues functioning as networkmodifiers is then 2.

A sufficient amount of (activated) (meth)acrylic acid is provided,single-stage or two-stage, for the preparation of the silanes accordingto the invention so that a molecule with two (meth)acrylic acid amideresidues is produced. Should the starting silane contain one or twohydroxyl or thiol groups instead of one or two amino groups, in eachcase the corresponding (meth)acrylic acid esters or (meth)acrylic acidthioesters would be formed. When the starting silane contains a furtherprimary amino group instead of the secondary amino group, a compoundwith two primary (meth)acrylamides is produced.

In the second step of the reaction, one of the two double bondsintroduced by binding of the (meth)acrylic acid group in the molecule isused for a thiol-ene addition. With this reaction, a sulfonic acid groupis introduced into the molecule. In a comparable manner, a sulfate groupcan be introduced.

Concerning the employable starting compounds for reaction 2, what hasbeen said in regard to reaction 1 applies. The reaction control differsfrom reaction 1 in that in a first step it is not (meth)acrylic acid,but another, optionally activated carboxylic acid that is being usedwhich has a C═C double bond, preferably in combination with a C═O group(i.e. a Michael system containing the structure C═C—C═O). In theexample, the anhydride of maleic acid was used. The latter, on accountof the somewhat different reactivity of the primary and the secondaryamino groups, binds surprisingly exclusively to the primary amino groupprovided that it is not used in excess; the carboxylic acid group thatis released in this reaction is not reactive enough to attack at thesecondary amino group so that exclusively, or almost exclusively, aproduct is produced as shown in the reaction in an exemplary way. Thelatter is reacted afterwards with activated (meth)acrylic acid. Finally,with the aid of sodium sulfite, a sulfonate group can be added to thedouble bond of the maleic acid residue which can be converted, asneeded, in a known manner into a sulfonic acid group.

The product carries, in addition, a free carboxylic acid group which canbe used either for an even more improved adhesive and etching effect or,as needed, can be reacted further, e.g., complexed.

This reaction is particularly characterized in that, by selecting theindex n, the ratio of (meth)acryl groups to sulfonic acid groups andcarboxylic acid groups can be adjusted as needed.

A reaction according to variant (B) will be explained below in anexemplary fashion with the aid of the reaction 5 in more detail.

Concerning the variability of the starting silane, reference is beinghad to the explanations in regard to the reactions 1 and 2 which applyin a comparable manner also to the reaction 5. Only the presence of astrained and thus reactive hetero ring is mandatory in the hydrocarbongroup. In the selected example, this is a terminal epoxy group. However,the reaction could also be carried out, instead, with an aziridine or athiocyclopropyl group. Then, in the first step an amino or a thiol groupwould result instead of a free hydroxyl group. However, when instead ofa strained three-membered ring a cyclic carbonate is used, the reactioncan be carried out only according to the variant b) shown in reaction 5.

When the three-membered ring is reacted directly with a sulfite or asulfate, an ethylene or ethyleneoxy bridge will be formed mandatorilybetween the SO₃Na or SO₃H group and the linking site for the subsequentesterification of the hydroxyl group produced in the first step with(activated) (meth)acrylic acid. Incidentally, reaction 5 is an examplefor the ability to couple also two (meth)acrylate residues to analkylsilane group. Instead of an aminoalkane sulfonic acid, in all casesa thio or a hydroxyalkane sulfonic acid can also be used in reaction 5,by the way. When a thio or hydroxyalkane sulfonic acid is used, there ishowever no binding of a second methacrylate residue; rather, the residuewhich is bonded in the variant b) by the sinuous line-shaped linkremains a thio or oxyalkane sulfonate group. Even when (meth)acrylicacid is used in less than stoichiometric quantity, binding of only one(meth)acrylate residue occurs. Binding occurs at the most basic one ofthe available groups, i.e., at the only one or the most basic aminogroup, provided the latter is present.

When a thioalkane sulfonic acid is used, a thioether group is produced.A molecule according to the product of reaction 5 with this group, butwithout silyl residue, can be considered also in conformity with theinvention in view of some aspects.

A reaction according to variant (C) will be explained below in anexemplary fashion with the aid of the reaction 6 in more detail.

Concerning the variability of the starting silanes, reference is beinghad again to the explanation in regard to the reactions 1 and 2 whichapply in a comparable manner also to the reaction 6. The length andother configuration of the alkyl group at the silicon atom can beselected freely, provided it has a primary amino group. To the latter,first an alkenyl sulfonate and afterwards (activated) (meth)acrylic acidare coupled; the sulfonate can be converted, as in the remainingreaction sequences, in a suitable manner into the free sulfonic acidgroup afterwards.

The preceding reaction examples show reactions to sulfonates. By the useof sulfates instead of sulfites, as disclosed in U.S. Pat. No.6,777,521, the corresponding sulfate compounds can be obtained in thereactions according to variant (B).

A reaction according to variant (D) will be shown below in an exemplaryfashion with the aid of reaction 4:

This reaction is characterized in that it is possible, by selecting themolar quantity of sulfonic acid compound, to obtain compounds with two(meth)acryl residues and one sulfonic acid residue (when using one molsulfonic acid compound per one mol of methacrylate) or, when double themolar quantity is used of sulfonic acid compound, compounds with one(meth)acryl residue and two sulfonate residues. When anon-stoichiometric quantity of sulfonate is used, molecule mixtures canbe obtained at will.

The preceding reaction examples show reactions to sulfonates. By usingsulfates, as disclosed in U.S. Pat. No. 6,777,521, instead of sulfitesin the reactions according to variant (B), corresponding sulfatecompounds can be obtained.

Inasmuch as the compounds according to the invention are silanes, theycan be hydrolytically condensed by usual methods (in particular, the solgel process); silicic acid polycondensates are produced in this way,also known as ORMOCER®e. These are also encompassed by the invention.The condensation reaction can occur in the presence of additionalsilanes of the formula SiR*_(a)R**_(4-a) which are known in the art invery large numbers. R* means herein a hydrolyzable group which enablesthe incorporation by condensation of the silane into the network, whileR** can be any non-condensable residue. When other metal compoundsshould be additionally present in the condensation reaction, e.g.,alkoxy compounds of aluminum, titanium, zirconium or tin, a silicic acid(hetero) polycondensate is generated in which the aforementioned metalatoms are integrated into the Si—O—Si network. R* can be, as needed, ahalide like Cl, hydrogen, acyloxy with preferably 2 to 5 carbon atoms,alkylcarbonyl with preferably 2 to 6 carbon atoms, or alkoxycarbonylwith preferably 2 to 6 carbon atoms. In some cases, R* can also be NR²with R² being hydrogen, alkyl with preferably 1-4 carbon atoms, or arylwith preferably 6-12 carbon atoms.

It can be desirable to provide additional metal compounds for theincorporation by condensation into the inorganic network. For thispurpose, in particular hydrolytically condensable compounds of metals ofthe main groups III and IV as well as of the transition metal groups IIIto VI are suitable, e.g., of boron, aluminum, titanium germanium,zirconium or tin. These metal compounds are known in large numbers. Inthese cases, a silicic acid (hetero) polycondensate is generated inwhich the afore mentioned metal atoms are integrated into the Si—O—Sinetwork. The additional metal compounds are often alkoxy compounds; inspecific embodiments of the invention, the other metal compoundsthemselves can also have reactive groups however. In this context, ofspecial interest for the present invention are complexes whichthemselves carry (meth)acryl groups because the latter can be integratedby a subsequent organic polymerization into the organic network.

The reactions and thus the introduction of the sulfonic acid or sulfategroups can be carried out completely or partially at the stage after thepolycondensation (usually a sol gel step) instead of at the silanestage, i.e. after building the inorganic polymer structure.

Independent of whether the compounds according to the invention containsilyl groups or not, they can be subjected on account of the available(meth)acryl group(s) to an organic polymerization. The materialsresulting therefrom and cured by the polymerization are also encompassedby the invention.

Of course, condensed silanes can also be furthermore cured organically.Materials cured in this way which contain an inorganic Si—O—Si network,optionally with additional cations as mentioned above, as well as anetwork which has been generated by polymerization of methacryl groupsare encompassed by the invention.

The syntheses that can be used according to the invention arecharacterized by simple reaction control, a low number of working steps,and good yields.

As partially already mentioned above, in specific embodiments of theinvention a compound can be substituted with more than one sulfonic acidgroup or sulfuric acid group and/or with more than one (meth)acrylgroup. By the presence of more than one (meth)acryl group, the networkwhich forms upon polymerization can become even more fine-meshed. Inthis context, it should be noted that by the contents of polymerizabledouble bonds the modulus of elasticity of the future organicallypolymerized polymer can be adjusted in such a way that the polymerbecomes more or less flexible and thereby less hard or harder. By thepresence of more than one sulfonic acid group or sulfuric acid group,the etching effect of the material is further increased.

The inventors have surprisingly found that already with low sulfonicacid contents an enormous etching effect on the dental tissue can beobserved. This can be demonstrated by means of a comparison of theaverage roughness of the enamel surface: Polished enamel has an averageroughness of about 0.21 μm, measured with an optical profilometer of thecompany UBM. With a phosphonic acid-functionalized silicic acidpolycondensate of glycerin-1-methacryloyl-2-(siloxypropyl) carboxymethylphosphonic acid, roughness in the range of 0.33 μm can be achieved. Withcondensates of the compounds according to the invention, the roughnessis within the range of more than 0.45 μm. Dental enamel images are shownin the FIGS. 1 a and 1 b.

The compounds according to the invention, namely the silanes as well asthe purely organic compounds, are generally water-dissolvable which canbe advantageous in many respects. This may have to be expected.Nevertheless, the inventors were surprised of the fact that also thesilicic acid polycondensates generated from the silanes are generallywater-soluble even though they carry a plurality of (meth)acrylategroups. This has great advantages for many uses wherein medicalapplications should be mentioned foremost. For the condensates can beapplied in aqueous medium, i.e. can be applied in any form without theuse of a non-aqueous solvent being required. But also for industrialapplications water-based reactions are always advantageous, namelyalready for reasons of occupational safety and the environmentalcompatibility.

The possibility of forming further reactive groups in the compoundsaccording to the invention, aside from the sulfonic acid function, opensup additional possibilities. Thus sulfonic acid groups have a strongeretching effect than carboxyl groups, while the latter havecomplex-forming properties. Provided that additional hydroxyl groups arepresent, they can be used either for the improvement of wetting of thebase surface or for the further reactions which can further modify thecompounds according to the invention. One example is complexing or areaction with a dicarboxylic acid (which can be effected, e.g., with theaid of correspondingly activated acid molecules).

In addition to the degree of polymerization and etching effect, thegroups and residues on the compounds of the invention have otherproperties which are favorably for several applications: The sulfonateor sulfate group is a charge carrier for which reason uses are possibleas electrophoresis gels, as materials for the electrophoretic coating oras materials that modify conductivity or antistatic properties.Moreover, the group can serve as an acidic catalyst, namely, on the onehand, for the sol gel process in case of a hydrolytic condensation ofthe silanes according to the invention (a later separation step for thecatalyst separation can then be dispensed with) and, on the other hand,in respect to the future use (an example are the mesoporous membraneswith sulfonic acid groups which can serve as catalyst for chemicalprocesses). The group provides furthermore a good solubility in polarmedia. Particularly for dental purposes, but not exclusively for thispurpose, it serves as an adhesion promoting group for inorganic, organicas well as hybrid surfaces. Like carboxylic acid groups, it can alsoform ionic bonds by means of which e.g., alkali, alkaline earth,ammonium, Ti, Zr, Sn, Ca and other suitable cations can be incorporatedin the form of their salts into the polycondensate network. In this way,several modification or material-specific adjustments, e.g., concerningthe X-ray opacity, the refractive index or the contact toxicity, can beachieved. The refractive index is moreover influenced (increased) by thepresence of a thioether group. By the sulfonate groups or sulfate groupsin the material, the material is moreover imparted with an antimicrobialeffect. But the invention can be applied also in quite different fieldsbecause e.g. proton-conducting membranes, e.g., for fuel cells, can beformed with sulfonate group-containing or sulfate group-containingmaterials. Further, the materials are suitable e.g. as an ion exchanger,as a pseudo-static phase in the electric-kinetic chromatography or assubstances with interfacial tension lowering action (detergent).

In particular by the combination of the sulfonate or sulfate groups andoptionally additionally the —CO₂H groups withpolymerizable/polyaddition-capable double bonds in a molecule, thecompounds lend themselves to the use in the medicine sector(specifically dental field), e.g., as an adhesion promoter and as amatrix component for cements. The adjustment of the refractive index cancontribute to the increase of the translucence of the dental materialand thus to its approximation to the natural tooth material.

With the functionalized compounds according to the invention, compoundsare available which can be used, on the one hand, directly (e.g., forthe functionalization of surfaces) and, on the other hand, providedsilanes are concerned, can serve as starting compounds for thepreparation of inorganic hydrolysates/condensates (resin systems) aswell as inorganic/organic composite polymers (matrix systems), i.e.after organic polymerization/polyaddition (curing) with differentproperties. With the silane-free monomers purely organic polymermaterials or polymers can be obtained. By use of any filler materials(particles, fibers), as for example the particles disclosed in DE1064378, DE 19832965, DE 10018405, DE 1041038 as well as inDE102005018351, corresponding composites are obtained. These plasticallyprocessible composites are characterized by very high filler contentsthat are possible (see nanohybrid composites) in combination with anexcellent processibility. Therefore, different properties can beadjusted and matched to the requirements in wide ranges for thecompounds according to the invention or the silanes and the resinsystems, matrix systems or purely organic polymers as well as the filledsystems (composites) obtainable therefrom.

In accordance with the intended special purpose of use, suitableadditives can be added to the silicic acid (hetero) polycondensates orthe compounds to be organically cured, such as initiators, coloringagents (dyes or pigments), oxidation inhibitors, polymerizationinhibitors (for avoiding a premature polymerization), leveling agents,UV absorber, stabilizers, microbiocidal active ingredients or the like,as is known to a person of skill in the art. Examples of polymerizationinitiators are initiators for radical polymerization, namely for thermalcuring like peroxides (e.g., benzoyl peroxide) or photo initiators likebenzophenone, camphorquinone or combinations of α-diketones with amineas a reducing agent, as for example disclosed in DE 199 03 177 C2. Forthe dual curing of radically and cationically polymerizable systems, inparticular diaryl iodonium or triaryl sulfonium salts can be added forwhich the aforementioned publication also provides examples.

A filled dental composite (i.e. an organically not yet crosslinkedfilled resin of hydrolyzed and condensed silanes according to theinvention), after it has been applied for the intended purpose, can becrosslinked in a suitable manner organically and thus be cured. Aboveall, an organic polymerization of the (meth)acrylate groups is used forthis purpose. The silane-free compounds can also be converted by apolymerization of this group into a polymer. This is a radicalpolymerization that usually occurs with addition of radical starterslike the above mentioned ones and optionally known activators, withexposure to e.g. visible light (blue light; dental irradiator), i.e.photochemically, thermally or redox-induced, but also occurs within thescope of 2-component reactions or anaerobically. The combination of selfcuring action with e.g. photo-induced or thermal curing is alsopossible.

The use of such materials applies inter alia to the use in the form ofbulk materials, composites, cements, adhesives, potting compounds,coating materials, adhesion promoters, binding agents for ceramicparticles (ceramic shaping processes), producing or priming of fillersand fibers, use in reaction extruders and the like for most differentpurposes (in particular for medical, but also for (micro)optical and(micro)electronic applications).

Below, preparation methods for the above reactions are provided in anexemplary way.

Reaction 1:

Stage 1: 5.11 g (0.024 mol) N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane was dissolved in 5.21 g triethylamine and 30 mltoluene and was cooled to 0° C. Afterwards, 5.0 ml (0.051 mol)methacrylic acid chloride in 30 ml toluene were added dropwise. Thereaction mixture was stirred for 3 h at room temperature. The mixturewas centrifuged and the obtained solution adjusted for hydrolysis andcondensation with 1 N hydrochloric acid to pH 1-2. After 24 h thevolatile components were removed under vacuum.

Stage 2: 3.92 g (0.013 mol) of the product of stage 1 were dissolved in30 ml ethanol, the solution adjusted with sodium hydroxide to pH 10, andheated to 60° C. Afterwards 1.93 g (0.015 mol) sodium2-mercaptoethansulfonate dissolved in 40 ml H₂O were added dropwise,followed by stirring for 4 h. Ethanol was removed under vacuum and theaqueous solution treated with a cation exchanger. The volatilecomponents were removed under vacuum. The end product is redissolvablein water.

Reaction 2:

Stage 1: 8.69 g (0.042 mol) N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane were dissolved in 50 ml ethyl acetate and heatedto 50° C. A solution of 4.23 g (0.043 mol) maleic acid anhydridedissolved in 30 ml ethyl acetate was added dropwise, followed bystirring for 19 h. The mixture was centrifuged and the residual materialpurified twice with ethyl acetate and dried under vacuum.

Stage 2: 6.06 g (0.021 mol) of the product of stage 1 were dissolved in5 ml water and 1.72 g NaOH and cooled to 0° C. 2.1 ml (0.021 mol)methacrylic acid chloride were slowly added dropwise with strongstirring action, followed by stirring for 5 h at 50° C. Afterwards, thevolatile components were removed under vacuum.

Stage 3: 9.82 g (0.021 mol) of the product of stage 2 were dissolved in20 ml water and heated to 60°. Afterwards, 2.61 g (0.021 mol) sodiumsulfite were added dropwise with stirring action, followed by stirringfor 24 h. The aqueous solution was treated with a cation exchanger andthe volatile components were removed under vacuum. The product can beredissolved in water.

Reaction 5:

a)Stage 1: 5.04 g (0.040 □mol) sodium sulfite were dissolved in 30 ml H₂Oand heated to 80° C. A solution of 9.96 g (0.040 □mol) 3-glycidoxypropylmethyldiethoxysilane in 10 ml ethanol was added dropwise, followed bystirring under reflux for 3 h.

After evaporation of ethanol, the aqueous phase was purified with ethylacetate and afterwards the volatile components were removed undervacuum.

Stage 2: 5.04 g (0.016 mol) of the product of the stage 1 were dissolvedin 10 ml water and 2.79 g (0.070 □mol) NaOH and cooled to 0° C.Afterwards, 4.0 ml (0.016 mol) methacrylic acid chloride were addeddropwise and the reaction mixture stirred for 4 h at 30° C. The solutionwas purified with ethyl acetate, the aqueous phase treated with a cationexchanger, and the volatile components removed afterwards under vacuum.The product can be redissolved in water.

b)

Stage 1: 3.38 g (0.027 mol) 2-aminoethane sulfonic acid were dissolvedin 40 ml H₂O and adjusted with 1 N NaOH solution to pH 14. A solution of6.81 g (0.027 mol) 3-glycidoxypropyl methyldiethoxysilane in 30 mlethanol was added dropwise at 50° C., followed by stirring for 3 h. Thenethanol was removed under vacuum and the aqueous solution was purifiedwith ethyl acetate. Afterwards the volatile components were removedunder vacuum.

Stage 2: 5.12 g (0.014 mol) of the product of stage 1 were dissolved in10 ml water and 2.58 g (0.065 mol) NaOH and cooled to 0° C. 1.5 ml(0.016 mol) methacrylic acid chloride were added dropwise and thereaction mixture stirred for 4 h at 30° C. The aqueous solution waspurified with ethyl acetate and was treated with a cation exchanger.Afterwards the volatile components were removed under vacuum. Theproduct can be redissolved in water.

Reaction 6:

Stage 1: 5.14 g (0.027 mol) 3-aminopropyl methyldiethoxysilane weredissolved in 30 ml ethanol and 1.65 g (0.016 g) triethylamine and heatedto 70° C. Afterwards 14 ml (0.027 mol) aqueous 25% sodium vinylsulfonatesolution were added dropwise, followed by stirring for 24 h. Afterwardsethanol was removed under vacuum and the aqueous solution was washedwith ethyl acetate. Afterwards the volatile components were removedunder vacuum.

Stage 2: 5.73 g (0.018 mol) of the product of stage 1 was dissolved inin 10 ml water and 2.92 g (0.075 mol) NaOH and cooled to 0° C. 1.8 ml(0.018 mol) methacrylic acid chloride were added dropwise and thereaction mixture stirred for 5 h at 30°. Afterwards the solvent wasremoved under vacuum. The aqueous solution was purified with ethylacetate and was treated with a cation exchanger. Afterwards the volatilecomponents were removed under vacuum. The product can be redissolved inwater.

Reaction 4:

1.50 g (0.005 mol) trimethylpropane triacrylate and 13.9 mg (0.06 wt. %)butylhydroxytoluene were dissolved in 20 ml ethanol and heated to 40° C.0.87 g (0.005 mol) sodium 2-mercaptoethanesulfonate were dissolved in 20ml water and added dropwise. The reaction mixture was stirred for 4 hand ethanol was removed afterwards at 40° C. under vacuum. The aqueoussolution was purified afterwards with ethyl acetate, treated with acation exchanger, and the volatile components were removed under vacuum.The product can be redissolved in water.

What is claimed is: 1-21. (canceled)
 22. A compound comprising at leastthree functionalities, including: a first functionality (a) that is asulfonate group or a sulfate group of the formula —(O)_(d)—SO₃M with d=0or 1 and with M=hydrogen or a monovalent metal cation or a correspondingportion of a multivalent metal cation; a second functionality (b) thatis a first (meth)acryl residue; and a third functionality (c) that iseither (c1) at least one second (meth)acryl residue or an inorganicallycondensable group, and/or (c2) a carboxylic acid function, and/or (c3) afunction by which the refractive index of a material made from thecompound is increased and that is a thioether group; with the provisothat, when the compound is free of silicon, the sulfonate group or thesulfate group and the first or second (meth)acryl residue are separatedfrom each other by a hydrocarbon-containing residue having a carbonchain, wherein the carbon chain either is interrupted by O, S, or NH orthe carbon chain contains a linking group.
 23. The compound according toclaim 22 with the formula (II)

wherein R¹ is a bivalent hydrocarbon residue which, provided that f=1,is bonded by a carbon atom to the silicon atom, R⁹ is H or alkyl or, incase of a=0, f=1, and g=1, can be additionally a hydrolyticallycondensable residue or

R³ is an alkylene that is unsubstituted or substituted with a functionalgroup, straight-chain, branched or has at least one cyclic structure, Ais a linking group, R⁴ is a hydrocarbon group that is optionallyinterrupted by O, S, NH or NR⁸ and/or optionally functionallysubstituted, preferably is an alkylene of this type, M is hydrogen or amonovalent metal cation or the corresponding portion of a multivalentmetal cation, preferably selected from alkali and alkaline earthcations, in particular Na, K, ½ Ca, ½ Mg, or ammonium, R⁵ and R⁶,independently of each other, are either residues that are condensableunder hydrolysis conditions or alkyl, aryl, arylalkyl, alkylaryl oralkylarylalkyl substituted or unsubstituted, straight-chain, branched orhaving at least one cyclic structure, in exceptions instead also acorresponding alkenyl, arylalkenyl, or alkenylaryl, R⁸ is alkyl withpreferably 1 to 6 or alkenyl with preferably 2 to 6 carbon atoms or a(meth)acryl residue, B is vinyl, 2-allyl or, in case of e>1, an organicresidue with e vinyl groups that are present in each case bonded to agroup located in the curly brackets, Y is a nitrogen atom, —O—CH═,—S—CH═ or —NH—CH═, wherein in each case the oxygen atom, the sulfur atomor the NH group has a bond to the adjacent C(O) group, a is =0 or 1, bis =0 or 1, c is =0 or 1, d is =0 or 1, and e is =1, 2 or 3 f is =0 or 1and g is =0 or 1, wherein, when f is =1, then a and g both are ≠0, andwherein, when f is =0, then at least one of the residues R³ or R⁴carries a functional substituent which has a (meth)acryl residue or anacidic group or R⁴ is an alkylene that is interrupted at least by S. 24.The compound according to claim 23, wherein at least one of the residuesR³ and R⁴ is substituted with at least one hydroxyl group and/or with aresidue R¹⁰COOM and/or with a residue SO₃M, wherein M is defined as inclaim 22, wherein R¹⁰ is a chemical bond or a C₁-C₆ alkylene residue.25. The compound according to claim 23, wherein f=0, g=0, and a=0. 26.The compound according to claim 23, with the proviso that, when Y is anitrogen atom, b=0 and c=0, the residue R³ means optionally substitutedethylene, and, when Y is a nitrogen atom, b=0 and c=1, the residue R⁴ isan alkylene that is interrupted by O, S, NH or NR⁸ and optionallyfunctionally substituted, wherein preferably in each case d is also =0.27. The compound according to claim 23, wherein the linking group A inthe formula (II) is selected from (read from the left to the right inthe formula II) C(O)NH, NHC(O), NR⁸C(O), C(O)O, and OC(O), wherein R⁸ isalkyl with preferably 1 to 6 or alkenyl with preferably 2 to 6 carbonatoms or a (meth)acryl residue.
 28. The compound according to claim 22that is a silane of the formula (I)R⁷ _(a)R² _(b)SiZ_(4-a-b)  (I) wherein R⁷ is a hydrolyticallycondensable residue; R² is an alkyl, aryl, arylalkyl, alkylaryl oralkylarylalkyl that is substituted or unsubstituted, straight-chain,branched or has a cyclic structure or is a corresponding alkenyl whosecarbon chain in all cases optionally can be interrupted by —O—, —S—,—NH—, —S(O)—, —C(O)NH—, —NHC(O)—, —C(O)O—, —C(O)S, —NHC(O)NH—, orC(O)NHC(O) groups which can optionally be oriented in both possibledirections; Z is a residue in which are present at least one (meth)acrylgroup and either at least a sulfonate group or a sulfate group that arebonded directly or indirectly by an unsubstituted or substitutedhydrocarbon group via an Si—C bond to the silicon atom; a is 1, 2 or 3;b is 0, 1 or 2; and a+b together are 2 or
 3. 29. The compound accordingto claim 28 with the formula (Ia)

wherein R¹ is a hydrocarbon group bonded by a carbon atom to the siliconatom, as it has been defined above, R⁷ is a hydrolytically condensableresidue, R³ is an alkylene that is unsubstituted or substituted with afunctional group, straight-chain, branched or has at least one cyclicstructure, R⁴ is a hydrocarbon group that is optionally interrupted byO, S, NH or NR⁸ and/or optionally functionally substituted, preferablyis an alkylene of this type, R⁵ and R⁶, independently of each other, areeither residues that are condensable under hydrolysis conditions oralkyl, aryl, arylalkyl, alkylaryl or alkylarylalkyl substituted orunsubstituted, straight-chain, branched or having at least one cyclicstructure, in exceptions instead also a corresponding alkenyl,arylalkenyl, or alkenylaryl, B is vinyl, 2-allyl or, in case of e>1, anorganic residue with e vinyl groups that are present in each case bondedto a group located in the curly brackets, Y is a nitrogen atom, —O—CH═,—S—CH═ or —NH—CH═, wherein in each case the oxygen atom, the sulfur atomor the NH group has a bond to the adjacent C(O) group, b is =0 or 1, cis =0 or 1, d is =0 or 1, and e is =1, 2 or 3
 30. The compound accordingto claim 29, with the proviso that, when Y is a nitrogen atom, b=0 andc=0, the residue R³ means optionally substituted ethylene, and, when Yis a nitrogen atom, b=0 and c=1, the residue R⁴ is an alkylene that isinterrupted by O, S, NH or NR⁸ and optionally functionally substituted,wherein preferably in each case d is also =0.
 31. The compound accordingto claim 29, wherein the linking group A in the formula (Ia) is selectedfrom (read from the left to the right in the formula Ia) C(O)NH, NHC(O),NR⁸C(O), C(O)O, and OC(O), wherein R⁸ is alkyl or alkenyl withpreferably 1 to 6 or 2 to 6 carbon atoms or a (meth)acryl residue. 32.The compound according to claim 29, wherein at least one of the residuesR³ and R⁴ is substituted with at least one hydroxyl group and/or with aresidue R¹⁰COOM and/or with a residue SO₃M, wherein M is hydrogen or amonovalent metal cation or a corresponding portion of a multivalentmetal cation, wherein R¹⁰ is a chemical bond or a C₁-C₆ alkyleneresidue.
 33. A method for preparing a compound with the formula (II) asdefined in claim 23, the method comprising the steps of: (a) Providing ahydrocarbon compound which carries at least two functional groups,selected from primary amines, secondary amines, hydroxyl groups andthiol groups; (b) Reacting a first one of the two functional groups withoptionally activated (meth)acrylic acid and reacting the second one ofthe two functional groups with a carboxylic acid that is optionallyactivated and has a C═C double bond, wherein said carboxylic acid can be(meth)acrylic acid or a different double bond-containing carboxylicacid; and (c) Adding, subsequent to the step (b), a sulfonategroup-containing compound or a sulfate group-containing compound or asulfite to the C═C double bond of the carboxylic acid residue reactedwith said second functional group in such a way that on the (meth)acrylresidue reacted with said first functional group such an addition doesnot take place.
 34. The method according to claim 33, wherein thesulfonate group-containing compound or the sulfate group-containingcompound has an OH—, SH— or NHR¹¹-group, with R¹¹=hydrogen or C₁-C₆alkyl, and in particular an SH group.
 35. A method for preparing acompound of the formula (II) as defined in claim 23, the methodcomprising the steps of: (a) Providing a hydrocarbon compound whichcarries at least one hetero ring, selected from oxacycyclopropyl,azacyclopropyl, thiocyclopropyl, and a cyclic carbonate, (b) Reactingthe hetero ring with a sulfite or a sulfonate group-containing compoundor a sulfate group-containing compound, and (c) Reacting at least theOH—, SH— or NH₂-group generated in the step (b) with optionallyactivated (meth)acrylic acid.
 36. The method according to claim 36,wherein the sulfonate group-containing compound or the sulfategroup-containing compound has an OH—, SH— or NHR¹¹-group, withR¹¹=hydrogen or C₁-C₆ alkyl, and in particular an SH group.
 37. A methodfor preparing a compound of the formula (II) as defined in claim 23, themethod comprising the steps of: (a) Providing a hydrocarbon compoundwhich has an alkylamino group or a mercapto group, (b) Reacting analkenyl sulfonate with the alkylamino group or the mercapto group, and(c) Reacting the secondary amino group produced in the step (b) withoptionally activated (meth)acrylic acid.
 38. A method for preparing acompound of the formula (II) as defined in claim 23, the methodcomprising the steps of: (a) Providing an organic compound with at leastthree (meth)acryl groups, and (b) Adding a sulfonate group-containingcompound or a sulfate group-containing compound or a sulfite in lessthan stoichiometric quantity to the C═C double bond of one or several ofthe (meth)acryl groups such that the addition does not take place atleast at one (meth)acryl residue.
 39. A method for preparing a compoundof the formula (II) as defined in claim 23, the method comprising thesteps of: (a) providing a (meth)acrylsilane with at least two(meth)acryl groups, which are bonded by a carbon atom of a hydrocarbongroup to the silicon atom, and (b) adding a sulfonate group-containingcompound or a sulfate group-containing compound or a sulfite in lessthan stoichiometric quantity to the C═C double bond of one or several ofthe (meth)acryl residues such that the addition does not take place atleast at one (meth)acryl residue.
 40. A method for preparing a compoundas defined in claim 25, comprising: reacting an organic compound, whichhas at least one first (meth)acryl residue and at least onealkenylcarboxyl residue, with a sulfonate group-containing compound or asulfate group-containing compound or a sulfite so that the sulfonategroup-containing compound or the sulfate group-containing compound orthe sulfite is added to the C═C double bond of the alkenylcarboxylresidue in such a way that at the first (meth)acryl residue no suchaddition takes place; wherein the at least one alkenylcarboxyl residuecan be a second (meth)acryl residue or the residue of anotheralkenylcarboxylic acid.
 41. A silicic acid (hetero) polycondensateproduced by a hydrolytic condensation of the compound of claim
 23. 42.The silicic acid (hetero) polycondensate according to claim 41, producedby additionally using at least one hydrolytically condensable metalcompound of a metal, selected from metals of the main group III and IVand metals of the transition metal groups III to VI.
 43. The silicicacid (hetero) polycondensate according to claim 41, wherein the silicicacid (hetero) polycondensate is water-soluble.
 44. A silicic acid(hetero) polycondensate produced by a hydrolytic condensation of thecompound of claim
 28. 45. The silicic acid (hetero) polycondensateaccording to claim 44, produced by additionally using at least onehydrolytically condensable metal compound of a metal, selected frommetals of the main group III and IV and metals of the transition metalgroups III to VI.
 46. The silicic acid (hetero) polycondensate accordingto claim 44, wherein the silicic acid (hetero) polycondensate iswater-soluble.
 47. The polymerisate according to claim 44 in the form ofa dental material.
 48. A silicic acid (hetero) polycondensate producedby a hydrolytic condensation of the compound of claim
 29. 49. Thesilicic acid (hetero) polycondensate according to claim 48, produced byadditionally using at least one hydrolytically condensable metalcompound of a metal, selected from metals of the main group III and IVand metals of the transition metal groups III to VI.
 50. The silicicacid (hetero) polycondensate according to claim 48, wherein the silicicacid (hetero) polycondensate is water-soluble.
 51. A polymerisate,obtained from or by use of at least one compound as defined in claim 22by polymerization of at least some of the (meth)acryl groups.
 52. Thepolymerisate according to claim 51, comprising an inorganicallycondensed network of or with Si—O—Si bridges.
 53. The polymerisateaccording to claim 51 in the form of a dental material.
 54. Apolymerisate, obtained from or by use of at least one compound asdefined in claim 28 by polymerization of at least some of the(meth)acryl groups.
 55. The polymerisate according to claim 54,comprising an inorganically condensed network of or with Si—O—Sibridges.